Near field communication (NFC) tags, radio-frequency identification device (RFID) tags, Quick Response (QR) codes, and barcodes provide ways to store data. NFC and RFID tags transmit the stored data via wireless radio communication to nearby NFC or RFID readers. QR codes and conventional barcodes, on the other hand, are optical labels that can be read and interpreted by machine readers/scanners. At merchants' contactless point of sale (POS) terminals, consumers may use their electronic devices to supply payment information (e.g., credit card number) wirelessly.
The leading number of each reference number within the drawings indicates the figure in which that reference number is introduced and/or detailed. As such, a detailed discussion of reference number 101 would be found and/or introduced in FIG. 1. Reference number 201 is introduced in FIG. 2, etc.